1. Technical Field
The present invention relates to a gasification power generation plant, in particular, to warm-up operation of a gasifier.
2. Description of the Related Art
In coal gasification power generation plants in general, syngas is formed by gasifying coal in a gasifier, a gas turbine is driven by the generated syngas, and power is generated by a generator connected to the gas turbine. When the gasifier is started up by combusting startup fuel, such as diesel, natural gas, or the like, during startup operation of a coal gasification power generation plant, warm-up (warming) is performed to bring the interior of the gasifier to the dew-point or above in order to prevent sulfur contained in syngas generated from the startup fuel from causing acid-dew-point corrosion in a wall, a coal economizer, an evaporator, and so forth that form the gasifier and to prevent dust in the syngas from becoming deposited thereon.
Japanese Patent Publication No. 3676022 discloses a technique in which warm-up is performed for the interior of the gasifier by using inert gas, serving as warm-up gas, and supply water heated by an exhaust-heat recovery boiler (hereinafter, referred to as “high-temperature water”) is also circulated in the gasifier to perform the warm-up of the wall, the coal economizer, and the evaporator of the gasifier from the inside, thus reducing the warm-up operation time of the gasifier.